Electrode for illuminating purposes.



TINTTEB STATES PATENT OTFTCE.

ISADOR LADOFF, OF CLEVELAND, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, 0F THIRTY ONE-HUNDREIDTHS TO WALTER D. EDMONDS, OF BOONEVILLE, NEW

ELECTRODE FOR ILLUMINATING PURPOSES.

YORK.

1,033,762, Specification of Letters Patent. No Drawing. Application filed May 3, 1906.

To all whom it may concern Be it known that I, IsADoR LADOFF, a citizen of the United States, and a resident of the city of Cleveland, in the county of Guyahoga and State of Ohio, have invented certain new and useful Improvements in Electrodes for Illuminating Purposes, as, for instance, the Pencils of the Arc-Light, of which the following is a specification.

My researches and experiments have demonstrated that ordinary tita niferous iron ore so called, or say ilmenite, is capable, as such, of being manipulated and treated so as to produce directly therefrom an electrode, or say pencil, for the are light, possessing in the manufacture and use thereof exceptional and novel advantages, and my invention, in

its broadest aspect, consists in the selection and adaptation of the said substance, to wit, titaniferous iron ore, or ilmenite, for the purpose and to the use referred to.

My said improved pencils may be constructed as follows, it being understood that I do not limit myself to the specific method herein described, but that an important and leading feature of my invention will be realized by the use of any electrode or pencils composed substantially of the said substance, to wit, any natural ore containing in sufficient quantities and proportions for satisfactory illumination, among other things oxids of iron and titanium, together with the gangue of the ore. Taking for instance ore from the Adirondack region of the State of New York, containing in the neighborhood of 15 per cent. oxid of titanium and 82 per cent. oxid of iron, the said ore or substance is crushed, pulverized and ground preferably to the consistency of an impalpable powder. To this say 2 per cent. of pitch and some tar and some mineral oil is then added and mixed therewith as a binder and the mixture is then heated in any con venient manner as for instance by injecting steam until it is brought, as is preferable, to the consistency of a stifi putty. This is next shaped, by suitable stamps or otherwise, into cylindrical plugs. The plugs are then subjected to a pressure of from 8000 to 6000 pounds per square inch which may be applied by a steam heated hydraulic press or through any other convenient agency. On emerging from the press the electrodes appear as black rods having a smooth sur- Patented July 23, 1912.

Serial No. 315,108.

face. These rods are next cut into desirable lengths, packed in carbon or powdered calcined coke so as to be completely surrounded by the latter, and sand and clay applied to the exterior of the carbon so as to exclude access thereto and to the inclosed pencils by the air and thus create a reducing atmosphere around the pencils. The temperature of the mass is then raised to a moderate degree say 200 degrees centigrade, which is subsequently gradually increased until between 800 and 900 degrees centigrade have been attained, the increase being preferably uniformly graduated, and the period of con tinuous exposure to the said temperature covering preferably a period of several days. In one case, for instance, I began on the first day with a temperature of 260 degrees and continued gradually and continuously increasing the same through a period of ten days up to about 800 with Very satisfactory results, the pencils being of superior appearance, sufficient excellence and strength to meet all commercial requirements and giving, when burned in an arc lamp, an exceptionally desirable white light of high candle power with comparatively small expenditure of electrical energy.

Other than carboniferous binders might be used but my experience has demonstrated that the latter, by imparting a moderate addition of carbon, are advantageous both in the manufacture and resulting light. If the natural ore available in any particular case appears deficient in its content of oxid .of titanium, an additional per cent. of the latter may be readily imparted by adding same to the original pulverized mixture in the form of rutile, or otherwise. I prefer, as producing the best results, an ore containing by analysis from 15 per cent. to 40 per cent. of oxid of titanium and from 80 per cent. to per cent. of oxid of iron. Should carbon be introduced into the mass of the pencil as aforesaid by using a carboniferous binder or otherwise, such carbon may preferably constitute from one per cent. to ten per cent. of the mass of the pencil.

This invention is distinguishable from others previously made by me involving electrodes prepared from a mixture of magnetite and rutile in that, among other things, my present invention enables, with comparative economy, natural ores to be directly utilized in the construction of the pencil, and results in a pencil composed substantially of such ore treated as aforesaid, the constituents of the gangue under the conditions mentioned constituting an advantage to the production of the pencil and its desired candle power efliciency.

The treatment above described is believed to result in the reduction, in whole or in part of the oxid of iron of the ore likewise of the oxid of titanium, and it may be also in the reduction, decomposition and recombination of some of the ingredients or constituents of the gangue of the ore.

Having thus described my invention, what 15 I claim as new and desire to secure by Letters Patent is the following viz:

An are light electrode consisting essentially of compressed and partially fused Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

